Molly Ringwald, who became a teen idol for her roles in "Sixteen Candles," "Pretty in Pink" and "The Breakfast Club," is now 44 and living in Los Angeles with her husband, Panio Gianopoulos, and their three young children, Mathilda, Adele and Roman. Her debut novel, "When It Happens to You," released last month, is a series of interwoven stories whose main characters, Greta and Phillip, reel from the unraveling of their 18-year marriage.

Q:Why betrayal as the subject for your novel?

A: I felt like it was very universal. It could have something to do with my age. I feel surrounded by it. I wanted to write about it in as many ways as I could understand. The book starts with a marital betrayal, but the stories are really about all kinds of betrayal.

Q:I was intrigued by your characters Marina, a mom, and her son, Oliver, who calls himself Olivia and struggles with his gender identity. I wanted more of him, and wonder how you came up with the ending to his story, which felt abrupt.

A: All along, I had in mind a different ending, something more cinematic, like Olivia walking into school. But once I have Marina in that shop and Marina says (to the saleslady) that the dress "is for my daughter," that was it. Her answer just floored me. I've had the experience of my characters telling me what was going to happen when I didn't necessarily think that was going to happen.

Q:Didn't Bret Easton Ellis read this novel and comment on that particular scene, saying in his mind that Marina should have said, "It's for my son"?

A: Yes, Bret - I've known him since the '80s - read it and said that their story was haunting him. He was going back and forth on it.

Q:Have you thought about what you would do if your son announced he was a she?

A: I would like to think I would be like Marina, minus the freak-out she has. But I don't think you ever really know until you're in that situation.

Q:Did Easton Ellis blurb you?

A: He read the book in galley form, but he doesn't do blurbs. I have to say that the blurbing (asking other writers to endorse your book) is the worst part of the process. It's more excruciating than being reviewed.

Q:How do you find the actual writing process? Torture or fun or somewhere in between?

A: Somewhere in between. I enjoy having written. There's a lot of anxiety that goes into sitting down and starting. Some days it comes naturally, and that feels glorious, and other days it feels like you are trudging through cement that's drying.

Q:Where do you go to write?

A: I usually try to write in this sort of common shared writing space in L.A. that both my husband and I are part of. I get the most writing done there. But I'm a working actor and a mother, and some days it's not possible to get there. I write at home or on the set. This book - at least the note-taking part of it - was done on the set on my phone. I was in Canada filming this television show, "Psyche."

Q:Your husband is a writer, and your first reader and editor. Was it unsettling for him to read this work, given the marital mess?

A: I think sometimes he wonders where I get stuff from. But we are very inspired by a lot of the same things. We know the same people. We live a shared life.

Q:What did you think about Greta being open to the possibility of getting back together with Phillip?

A: I kind of imagined that as I was writing. But I didn't want them running off in the sunset together. I thought it was more interesting for them to muddle through and come to some place of forgiveness.

Q:How do you feel toward Phillip, whose betrayal is ugly and chronic?

A: I feel like with all my characters, he's flawed. He's made terrible mistakes, but he's not a bad person. I think he was suffering and not able to communicate. My personal feeling is that he wouldn't do it again. In the therapist's office, he confesses everything. He shows the darkest parts of himself. The hardest thing we can do is love another person knowing all of their imperfections.

Q:In what ways has your work in film influenced your writing?

A: Certainly it has helped with character development. I've always been more interested in character than anything. Detail is something I've always been interested in. I visualize things. I'm interested in the character's backstory.

Q:Were you always meant to be a writer and took a detour as an actor, or are the worlds symbiotic?

A: I think they're very symbiotic. I don't want to stop acting but I'm probably going to do more writing. I was writing all along, but I never knew I was going to publish something. I'm already in the note-taking mode for my next book.

Q:If this debut novel becomes a film, who will you play?

A: If the book became a film, which I'm hoping it does, I would want to play Marina. She's the only redhead.

Q:Why don't you turn it into a film?

A: I'm in the process of doing that. I'd want to direct, which would be a first for me. I am thinking about the structure of the book and how it would have to change for the film. I've been looking at different films and thinking about the best way to do it. I might collaborate with someone, as I'm so close to the material. I really love the characters, and the characters haven't let go of me.

Q:What are you reading?

A: I just finished "The Psychopath Test," by Jon Ronson, which is a rollicking good read. I'm reading a book by Meghan Daum, "Life Would Be Perfect If I Lived in That House."

Q:You're coming to San Francisco this week. Any favorite haunts?

A: I'm originally from Northern California, from Sacramento. My dad, who is a jazz musician, played a lot in San Francisco, and we would take trips there. There's a restaurant called Range that I love. They make a really good tomato salad. The last time I was there, they wrote the recipe down for me, and I carry it in my purse. I love San Francisco.

S.F. benefit: Molly Ringwald will be interviewed onstage in a fundraiser for Litquake by co-founder Jane Ganahl at 8 p.m. Thursday at the Verdi Club, 2424 Mariposa St., S.F. litquake.org.